We plan to study worksite factors related to alcohol consumption and alcohol-related problems in transit drivers who work for the City of San Francisco Municipal Railway (MUNI). Alcohol consumption in this ethnically mixed, blue collar population has a significant impact on the individual employees as well as on the operation of the transit system. The aims of this study are to (i) understand the overall pattern of alcohol use in the population of MUNI employees -- this includes quantity, frequency, and context of drinking and also drinking during and outside job hours; (ii) identify the range and extent of consequences of alcohol consumption in the MUNI population -- these include health, psychological, social, and financial consequences and will also include both consequences for the job (e.g., problems for family life, divorce, social behavior); and (iii) identify the major workplace and other factors which influence the level of alcohol consumption in MUNI employees -- these factors include: (i) official policy, (ii) workplace culture, (iii) social control, (iv) alienation, (v) job stress and (vi) the social and physical availability of alcohol. Use of the MUNI population for an in-depth study of blue-collar, workplace-related drinking has several advantages: (i) the MUNI population is a traditional blue-collar population -- results of the study should be relevant to other similar populations; (ii) we have already conducted extensive research in this population -- therefore, a baseline set of data exists for many medical, epidemiologic, and lifestyle variables; (iii) we have a history of working with both the union and Management -- therefore we have access to records and data bases set up and maintained by the MUNI management, and, more importantly, we have gained the cooperation and trust of both groups necessary for conducting research on this vitally important but sensitive topic. The study of alcohol and alcohol-related problems in this population is particularly important; the problem is of great concern not only to individual employees and their families, but to the organization itself -- issues of both public safety and efficiency are involved. The study will take place in a two-year period, using data collected during our extensive studies of this population, existing data from MUNI, and new data collected by surveys and interviews. Although not part of the present proposal, we expect that the proposed research will contribute directly to the development of effective primary and secondary prevention programs in the population.